40. Kate Phelan and Justin Cooke

Topshop has retail prowess—with more than 450 global stores and counting—but shines best online, thanks to clever tricks such as in-store photo booths that create shareable animated GIFs of shoppers in Topshop wares. Even for the tech-savvy fashion industry, Topshop is unusually astute. "We understand the power clothes have when photographed and presented in the right way," says Kate Phelan, formerly British Vogue’s fashion director. Her business partner Justin Cooke was global VP of public relations at Burberry. For a February show, they put live-streaming cameras on catwalking models, and fans chatted up Topshop’s team on Google Hangouts.